/*
* FLINT PARTICLE SYSTEM
* .....................
* 
* Author: Richard Lord
* Copyright (c) Richard Lord 2008-2011
* http://flintparticles.org
* 
* 
* Licence Agreement
* 
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* 
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/

package org.flintparticles.threed.initializers;

import org.flintparticles.common.particles.Particle;
import org.flintparticles.common.emitters.Emitter;
import org.flintparticles.common.initializers.InitializerBase;

/**
 * The ScaleAllInit Initializer sets the size of the particles image
 * and adjusts its mass and collision radius accordingly.
 * 
 * <p>If you want to adjust only the image size use
 * the ScaleImageInit initializer.</p>
 * 
 * <p>This initializer has a priority of -10 to ensure it occurs after 
 * mass and radius assignment classes like CollisionRadiusInit and MassInit.</p>
 * 
 * @see org.flintparticles.common.initializers.ScaleImageInit
 */

class ScaleAllInit extends InitializerBase
{
	public var maxScale(maxScaleGetter,maxScaleSetter):Float;
	public var minScale(minScaleGetter,minScaleSetter):Float;
	public var scale(scaleGetter,scaleSetter):Float;
	
	private var _min:Float;
	private var _max:Float;
	
	/**
	 * The constructor creates a ScaleAllInit initializer for use by 
	 * an emitter. To add a ScaleAllInit to all particles created by an emitter, use the
	 * emitter's addInitializer method.
	 * 
	 * <p>The scale factor of particles initialized by this class
	 * will be a random value between the minimum and maximum
	 * values set. If no maximum value is set, the minimum value
	 * is used with no variation.</p>
	 * 
	 * @param minScale the minimum scale factor for particles
	 * initialized by the instance.
	 * @param maxScale the maximum scale factor for particles
	 * initialized by the instance.
	 * 
	 * @see org.flintparticles.common.emitters.Emitter#addInitializer()
	 */
	public function new( minScale:Float = 1, maxScale:Float = -1 )
	{
		super();
		priority = -10;
		this.minScale = minScale;
		this.maxScale = Math.isNaN( maxScale ) ? minScale : maxScale;
	}
	
	/**
	 * The minimum scale value for particles initialised by 
	 * this initializer. Should be between 0 and 1.
	 */
	private function minScaleGetter():Float
	{
		return _min;
	}
	private function minScaleSetter( value:Float ):Float
	{
		_min = value;
		return value;
	}
	
	/**
	 * The maximum scale value for particles initialised by 
	 * this initializer. Should be between 0 and 1.
	 */
	private function maxScaleGetter():Float
	{
		return _max;
	}
	private function maxScaleSetter( value:Float ):Float
	{
		_max = value;
		return value;
	}
	
	/**
	 * When reading, returns the average of minScale and maxScale.
	 * When writing this sets both maxScale and minScale to the 
	 * same scale value.
	 */
	private function scaleGetter():Float
	{
		return _min == _max != null ? _min : ( _max + _min ) / 2;
	}
	private function scaleSetter( value:Float ):Float
	{
		_max = _min = value;
		return value;
	}
	
	/**
	 * @inheritDoc
	 */
	override public function initialize( emitter:Emitter, particle:Particle ):Void
	{
		var scale:Float;
		if( _max == _min )
		{
			scale = _min;
		}
		else
		{
			scale = _min + Math.random() * ( _max - _min );
		}
		particle.scale = scale;
		particle.mass *= scale * scale * scale;
		particle.collisionRadius *= scale;
	}
}
